1. Field of the Invention
The object of the invention is a software method of emulation of the EEPROM memory in another non-volatile memory, for example the Flash type memory. This method is applicable in systems, where in order to decrease costs of devices, using a non-volatile EEPROM memory, the existing memory is used, for example the Flash type memory for emulation of the EEPROM memory.
2. Brief Description of the Background of the Invention Including Prior Art
There is a hardware method of memory emulation in the integrated circuit itself, known from the European patent application number EP0991081. Its disadvantages are: firstly, limiting the emulation memory to one circuit and type of memory, secondly, a low ratio of a size of emulated EEPROM memory to a size of Flash memory used for the same purpose (1:8) and thirdly, a small size of the emulated memory, up to 8 KB.
Another method is known from publication written by Yvon Bahout, “Combined Flash and EEPROM Integrated Circuit,” Elektronik Industrie, vol. 28, No. 10, pp. 48, 50-51, October 1997. The method presents a cost-effective hardware only solution of a combined Flash and EEPROM chip. Each memory type block operates independently of the other during data writing. This results in that concurrent operation mode is possible and thus the Flash memory can be read while the EEPROM memory is being written.
Another hardware solution is the circuit, described in American patent document no. U.S. Pat. No. 5,651,128 presenting a memory, which consists of a matrix of cells and circuits, which enable programming of deletion of the emulated memory, the Flash type memory is used in the example of embodiment of the emulation.
In case of the described solutions, the emulation of the EEPROM memory is made with the use of a hardware solution, where the circuit uses the Flash type memory to store data both assigned for saving in the Flash memory as well as in the EEPROM memory.